<?xml version="1.0" encoding="utf-8"?>
<page xmlns="http://projectmallard.org/1.0/" type="topic" id="actions" xml:lang="zh-CN">
  <info>
    <title type="sort">1</title>
    <link type="topic" xref="query-execution-perspective"/>
    <link type="topic" xref="data-manager-perspective"/>
  </info>
  <title>操作</title>
  <p>
    Actions are bits of SQL code which depends on variables and can be executed from the contextual
    menu of any data set presented in a grid.
  </p>
  <p>
    For example if there is a table "products" which lists some kind of products and
    a table "comments" which lists all the comments left by users on a product (presumably
    the "comments" table will have a foreign key on the "products" table to reference it).
  </p>
  <p>
    An action can be defined to show all the entries in the "comments" table provided
    the key is defining a product. Then anytime a product is listed in a result set, the
    contextual menu will allow the user to execute this action and thus display all
    the comments on the selected product. This situation is illustrated in the following figures.
  </p>
  <p>
    The first step is to define an action, which is just a favorite in the <link xref="query-execution-perspective">query execution</link>
    perspective which is defined as an action: bring up the properties for the favorite, and
    make sure the "Is action" toggle is checked:
  </p>
  <figure>
    <title>Action - define an action</title>
    <desc>Define the action to list the comments for a product, from the query execution perspective</desc>
    <media type="image" mime="image/png" src="figures/action-4.png"/>
  </figure>
  <figure>
    <title>Action - display a list of products</title>
    <desc>In the query execution perspective, let's select all the products. Notice that
      there are here two defined actions: "Add comment on product" and "List comments
      for product"</desc>
    <media type="image" mime="image/png" src="figures/action-1.png"/>
  </figure>
  <p>
    Now let's pop up the contextual menu:
  </p>
  <figure>
    <title>Action - contextual menu</title>
    <desc>Pop up the contextual menu and select <guiseq><gui>Execute action</gui><gui>List comments for product</gui></guiseq></desc>
    <media type="image" mime="image/png" src="figures/action-2.png"/>
  </figure>
  <p>
    After a confirmation of the parameters to execute the action, the result is there:
  </p>
  <figure>
    <title>Action - executed</title>
    <desc>The action is now executed</desc>
    <media type="image" mime="image/png" src="figures/action-3.png"/>
  </figure>
</page>
